The present invention pertains to high-speed hand held rotary cutting machines and more particularly to an assembly for guiding and controlling the depth of the cut.
In working with wood or other materials, it is often desirable to remove a small but uniform amount of material along a pre-cut edge.
Powered, portable, hand-held rotary cutting tools are well known in the art such as the Dremel(copyright) and Moto(copyright) type tools used by model makers or similar personnel.
These powered, rotary cutting machines are often hand held and hand guided.
It is often very difficult to control the depth and straightness of the cut when guiding such machines by hand. The need in the art for a system for controlling the depth and straightness of the cut with a hand held rotary machine tool of this type has not yet been met.
The field of hand held rotary cutting machines is in need of improvements in the area of depth control and straightness of cut.
In addition, earlier machines do not address the need of protecting the operator from unnecessary exposure to an unshielded cutter.
The primary object of the present invention is to provide a guide accessory for easy attachment to commercially available hand held rotary cutting machines.
With the guide attachment, the rotary cutting machine is able to accurately and uniformly remove material. Examples are trimming wood or plastic model airplane parts for proper fit or chamfering sharp edges.
Another object of the invention is to help shield the operator from the dust and debris of the cutting operation.
A further object of this invention is to limit the operator to cutting tool exposure.
Another object of this invention is to protect the cutting tool from damage.
The present invention employs a novel, stepped guide to limit and control the depth of cut.
This invention provides an in-feed guide surface, offset a distance from the cutting circle and an out-feed guide surface parallel to the in-feed surface and tangent to the cutting circle. This difference in the distance from in-feed to out-feed surfaces is the amount of material removed.
In operation, the leading or in-feed surface of the guide is placed in contact with the surface of the workpiece. As the cutting machine is advanced into the workpiece, the exposed portion of the cutter removes material, allowing the out-feed or tangent surface of the guide to ride on the newly cut work-piece surface.
Other objects and advantages of this invention will be apparent from the following description when read in reference to the accompanying drawings.